DESCRIPTION

The pthread_mutexattr_getprioceiling() and pthread_mutexattr_setprioceiling()
functions, respectively, shall get
and set the priority ceiling attribute of a mutex attributes object
pointed to by attr which was previously created by the
function pthread_mutexattr_init().

The prioceiling attribute contains the priority ceiling of initialized
mutexes. The values of prioceiling are
within the maximum range of priorities defined by SCHED_FIFO.

The prioceiling attribute defines the priority ceiling of initialized
mutexes, which is the minimum priority level at
which the critical section guarded by the mutex is executed. In order
to avoid priority inversion, the priority ceiling of the
mutex shall be set to a priority higher than or equal to the highest
priority of all the threads that may lock that mutex. The
values of prioceiling are within the maximum range of priorities
defined under the SCHED_FIFO scheduling policy.

RETURN VALUE

Upon successful completion, the pthread_mutexattr_getprioceiling()
and pthread_mutexattr_setprioceiling()
functions shall return zero; otherwise, an error number shall be returned
to indicate the error.

ERRORS

The pthread_mutexattr_getprioceiling() and pthread_mutexattr_setprioceiling()
functions may fail if:

EINVAL

The value specified by attr or prioceiling is invalid.

EPERM

The caller does not have the privilege to perform the operation.

These functions shall not return an error code of [EINTR].

The following sections are informative.

EXAMPLES

None.

APPLICATION USAGE

None.

RATIONALE

None.

FUTURE DIRECTIONS

None.

SEE ALSO

COPYRIGHT

Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
-- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of
Electrical and Electronics Engineers, Inc and The Open Group. In the
event of any discrepancy between this version and the original IEEE and
The Open Group Standard, the original IEEE and The Open Group Standard
is the referee document. The original Standard can be obtained online at
http://www.opengroup.org/unix/online.html .